How to get a mean from multiple categorical fields I have some census data on income I would love to analyze. But income, in the data, is split into different income groups, each group is a column containing the number of people in an area that earns A to B. If my explanation doesn't make any sense please look at the table below. 
So basically I want to get the average income for an area. Can this even be done with data like this?

 A: You will probably not be able to get a good average income for an area without getting more specific data, but you might be able to attack this problem by making some approximations and checking them/following up.
Some assumptions you could make that come to my mind would be:


*

*Assume that on average most people in any given bin is at the average for that bin.

*If you want to be more slick you might have a better distribution within each bin. You could use this calculate the average in each bin and then you would be done. (eg maybe the distribution of data is log-normal)


The trick is if you can get the mean within a bin for an area you can then perform a weighted average. Most of the methods I listed would assume independence of the bin average as a function of area, but you might find that unacceptable. In that case you would need to try to reconstruct a function that calculates the average bin income as a function of area, which seems more ambitious than your original project.
